The invention disclosed herein relates to apparatus for changing the spacing between containers that are transported in a single lane on a belt-type or closed loop conveyor before the containers enter a machine, such as a labeling machine, in which they must have a specific space between them.
Mechanisms of the types mentioned are commonly employed in beverage container handling machines of various types. As the containers are transported on a belt conveyor in single file, a screw conveyor usually engages the containers in the form of bottles or cans and advances them in spaced apart relationship. The spacing for the last turn or groove or thread of the screw conveyor corresponds to the spacing required for the machine in which the containers are to be entered. Since container handling machinery is usually designed for processing containers of various sizes and shapes, apparatus for separating and spacing the containers should be adjustable. In addition, the containers in the apparatus that precedes the machine must be aligned to one common path that relates to the center point of the mouths or top openings of the containers for proper operation of the machine that follows.
Customarily there is a guide rail situated adjacent and generally parallel to the screw conveyor which is transversely displaced by a distance depending on the width of the containers and a section of rail situated directly across from the screw conveyor must also be angularlY adjusted, since the alignment of the containers in this area must agree with the path of the center point of the mouths of the containers. This can be done, for example, by using a screw conveyor having an increasing core diameter or an angularly adjustable screw conveyor having a constant core diameter.
In known apparatus of this type, guide rails supported on guide rods by clamps or by means of guides that have slots for sliding along fixed bolts, until now, have been adjusted by placing sample bottles or cans, that serve as a gage for the new size of the container in the first and last turns of the helical groove in the screw conveyor. This method is relatively time consuming since service personnel must loosen numerous bolted connections by hand, readjust the mentioned rail sections on the sample bottle size and then tighten them again. This work is particularly inconvenient and time consuming in labeling machines, since the guide rail located at the input to the labeling machine is difficult to access because the labeling mechanism is arranged at the back of the labeling machine table. Moreover, the conventional adjustment method using sample bottles is relatively inaccurate especially when the screw conveyor comprises a flexible contoured device where the helical groove of the screw is defined by brush bristles to form a configuration similar to the worm of a worm-wheel drive. Brush type screw conveyors are now commonly used for PET (polYethylene terephthalate) bottles. Sometimes the rail section is set so as to be too narrow whereupon the flow of containers is unnecessarily retarded and possibly jammed.